Opportunities for natural fiber reinforced composites towards tropical wind turbine material needs

Wind energy is one of the most widely adopted renewable energy harnessing methods around the world. Accordingly, wind turbine blades are gradually undergoing changes in design and geometry to make them more efficient. Tropical wind turbines require a different design structure due to the fact that wind speeds are low and turbine rotors cannot increase in size infinitely which would cause inertial problems. Hence a lightweight and sustainable solution could be found in natural fibre reinforced composites. In this study, epoxy resin is reinforced with flax fibre plain weave and twill weave fabrics (textile structure) using vacuum infusion method. Tensile testing of the natural fabric reinforced epoxy composites is performed according to ASTM D3039 standards. It is found that these composites are considerably weaker than Glass fibre reinforced epoxy composites (GFRPs). Thus, they may be used to manufacture non-load-bearing members of a wind turbine blade, which do not require stiffness comparable to glass or carbon fibre reinforced composites. Poor fibre-resin adhesion and the presence of voids have been observed as possible reasons for the reduced stiffness of the tested specimens. Future work includes testing of flexural strength, fatigue behaviour, etc. Depending on the results, other plant fibres laminated with thermoplastic/thermoset resins will be studied for comparison and the most suitable materials will be chosen for our wind turbine blade design.